---
name: "gnutls_psk_set_client_credentials_function2"
section: "3"
platform: "linux"
package: "gnutls"
version: "3.8.13-3"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/gnutls_psk_set_client_credentials_function2"
---

# gnutls\_psk\_set\_client\_credentials\_function2(3)

API function

## NAME

gnutls\_psk\_set\_client\_credentials\_function2 - API function

## SYNOPSIS

**#include \<gnutls/gnutls.h\>**

**void gnutls\_psk\_set\_client\_credentials\_function2(gnutls\_psk\_client\_credentials\_t** *cred***, gnutls\_psk\_client\_credentials\_function2 \*** *func***);**

## ARGUMENTS

- gnutls\_psk\_client\_credentials\_t cred

  is a **gnutls\_psk\_server\_credentials\_t** type.

- gnutls\_psk\_client\_credentials\_function2 \* func

  is the callback function

## DESCRIPTION

This function can be used to set a callback to retrieve the username and password for client PSK authentication. The callback's function form is: int (\*callback)(gnutls\_session\_t, gnutls\_datum\_t\* username, gnutls\_datum\_t\* key);

This callback function has the same semantics as that of **gnutls\_psk\_set\_client\_credentials\_function()**, but it allows non-string usernames to be used.

The  *username* and  *key* -\>data must be allocated using **gnutls\_malloc()**. The  *username* should be an ASCII string or UTF-8 string. In case of a UTF-8 string it is recommended to be following the PRECIS framework for usernames (rfc8265).

The callback function will be called once per handshake.

The callback function should return 0 on success. -1 indicates an error.

## REPORTING BUGS

Report bugs to \<bugs@gnutls.org\>.\
 Home page: https://www.gnutls.org

## COPYRIGHT

Copyright © 2001-2023 Free Software Foundation, Inc., and others.\
 Copying and distribution of this file, with or without modification, are permitted in any medium without royalty provided the copyright notice and this notice are preserved.

## SEE ALSO

The full documentation for **gnutls** is maintained as a Texinfo manual. If the /usr/share/doc/gnutls/ directory does not contain the HTML form visit

- https://www.gnutls.org/manual/